My 89 foxobdy still misfiring after many diagnostics ran. My mechanic did everything in his power besides head gasket job (which my car shows no sign of except it has 130 compression in cylinder 3 and cylinder 4 stays a lot colder than the rest of the cylinders). Cylinder 4 spark plug is significantly cleaner than the rest though.... With no oil leak, radiator mixing into plugs, no smoke, no bubbling in radiator, no obvious signs could it be a head gasket or something else?

we have done everything: new plugs and wires, bypassed vacuum, checked valves and roller rockers, leak down test, compression test, checked injectors, etc..... mechanic says only thing he can think is the head gasket??

It is boosted and has never been tuned because i just got it and went to tune it until we found the misfire.....

opinions?

 

please don't create duplicate threads, your other thread is working fine. thank you